Rear Spring Options

I have a 99 4x4 Tacoma V6 TRD and my springs in the back are sagging and I wanted to know if springs off of other trucks can give my car an additional height that are a direct bolt on. I currently have spacers in the front and back but i was told that the con of a spacer lift is rear spring sag. Any advice?

 

I don't know how much merit (or blame ) lift blocks should get for saggy springs , the Tacoma's fail & go saggy pretty well on their own, but yeah you should rid yourself of them front & rear, & yeah other springs from other vehicles can def. be a fix, click on the link in my sig for details...

 

x2 do this if you wanna haul something over 500 pounds without bottoming out